I have a 2003 astro van with towing pkg. has 150,000 the van has been what feels like hesitating while driving and just yesterday noticed when backing up it felt like van was in neutral but still in reverse but did take hold in just a few seconds, I recently changed fluid and filter and added lucas oil trans additive, also took to parts store to check an service eng soon light it showd no trans codes but did show crank pos.sensor ng. is it possible it is something other than a trans rebuild ? Thank You.!